Shooters Forum banner
1 - 10 of 10 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
Hello all. I thought I would come over to a US forum as you guys are probably the best to ask about this. I have an old Stevens mod 79 pump action that I’m having trouble with. Normally I wouldn’t bother with such an old gun but this one has a certain sentimental value.

Basically the issue is down to cycling cartridges. When you work the action it almost always fails to feed the next cartridge (jams the action) and you have to pull the action back again and then forward to get it to chamber it. Then sometimes when you open the action after a shot it will eject both the spent cartridge and the next live cartridge (when your down to your last shot you end up with a click rather than a boom it gets very annoying). I usually work with U/O shotguns so have very little experience with trouble shooting pump guns.

Can anyone give me any suggestions?
 

·
Registered
Joined
·
2,057 Posts
First, let me welcome you to this site! In regards to any old pump, or semi-auto shotgun: Make sure it is not loaded, then (and I'm not assuming any lack thereof) thoroughly detail clean and degrease the gun. Many times that is all that is needed! Next, if the cleaning doesn't work, you have learned a bit about the gun just by dis-assembling and putting it back together, so possibly you now know what is not working the way it's supposed to. Check with Numrich Gun Parts, Bob's Gun Parts, or any number of other sources if parts are available in this country. I believe you'll find the trouble when you clean the old girl!
 

·
Registered
Joined
·
2,255 Posts
Since you state it's more commonly occurring when you get down to the last shell in the tube, it sound like maybe a weak or compressed tube spring, and, or the tube / spring may be really dirty. Clean the tube and spring really well and see if that helps.

If the spring is compressed you can carefully stretch it a tad, just be careful not to over do it or you'll risk breaking it once you fill the tube back up with shells.

Or you can just buy another spring, and if you can't locate another Stevens spring, most pump shotguns tube springs are pretty similar and could be used as a substitute.

SMOA
 

·
Registered
Joined
·
3,202 Posts
Check the 'Cartridge Stop', it is held in place by a screw and nut. If the nut loosens the Cartridge Stop flops around and can cause problems. The nut should be tight enough to allow the Cartridge Stop to move freely, but not allow it to have side-play, nor bind if too tight.

Pay attention if you take the gun apart, loosen the buttstock before removing the trigger guard assembly, the 'Slide Lock Assembly' will probably fall away from the trigger guard assembly, and don't over tighten the buttstock bolt upon reassembly.
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #5 ·
Thanks for the info...

Bong Son Buck: As I have not had this gun in my possession for long, I can’t say as to when it was last cleaned properly. I will give it a full strip down tomorrow evening once my son has gone to bed. Other than pulling a bore snake through the barrel iv not done much cleaning.

Submoa: It is quite possible that this could be a key factor. Thanks to UK laws the tube gets molested so it can only accept 2 cartridges. It could be that this restriction has had a negative effect on the spring and the way it feeds. I should be able to inspect this when I strip it down for a good clean.

Mainspring: Another issue here perhaps. Just taking a quick look inside the action I can see that it’s not loose but the very tip of the cartridge stop appears to be very slightly bent/worn. Given that the gun is 37 years old it doesn’t surprise me if I find more worn parts. The wear on the cartridge stop seems to have only reduced the overall length of it by 1 or 2 mm at the most. Could this be an issue?

Again, thanks for the help guys. I will post further info once i have disassembled tomorrow.
 

·
Registered
Joined
·
3,202 Posts
Another issue here perhaps. Just taking a quick look inside the action I can see that it’s not loose but the very tip of the cartridge stop appears to be very slightly bent/worn. Given that the gun is 37 years old it doesn’t surprise me if I find more worn parts. The wear on the cartridge stop seems to have only reduced the overall length of it by 1 or 2 mm at the most. Could this be an issue?
The forward tip does not usually wear much, the rear tip can deform a bit with use. Always keep in mind that parts have been altered previously by someone. Check the Lifter Spring for decent tension against the Lifter Assembly.

I would cycle some ammo, preferably dummies, thru the action and try to identify when the malfunction occurs, and which part seems out of sync.
 

·
Registered
Joined
·
54 Posts
First make sure that it is scrupulously clean and try it.
If it keeps up you most likely need a Cartridge stop $10.60 from NUmrich
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #8 ·
OK :) finally had a chance (without child running around, don't like to do these things with very young kids around) and completely stripped the gun, even the trigger assembly.

Firstly, this is the first pump i have stripped, now i see why they generally don't break :D.

Secondly, i don't think this thing has been totally disassembled since it was put together in 1979. Although all of the components where very dirty with massive amounts of powder residue, the components themselves where actually in great shape, practically no wear. One interesting thing i found was that the magazine tube was not in alignment with the receiver, it was ever so slightly bent to one side :confused: this was easily fixed tho. So i cleaned the nuts out of the thing, reassembled and sparingly oiled where needed. It has already made a huge difference. The action is much smoother.

In order to test its cycling abilities (given that i couldn't just go outside and test fire), i found an old 3" spent casing and 2 snap caps. I fed the dead cartridge into the chamber, closed the action and then put 2 snap caps in the tube. I then cycled out all 3 (then repeat a few times). So far so good, FAR fewer stoppages. However i do appreciate that a spent casing and 2 snap caps cant really accurately represent the weight, balance and dimensions of an actual live cartridge so the true test will be out in the field.

Once I'm able to go out and test fire i will report back but that may be a week as we have stupid gun laws and i cant just go into the woods and fire a few.

Thanks for the help guys.
 

·
Registered
Joined
·
1,984 Posts
It is truly amazing the number of malfunctioning firearms that are fixed by simply cleaning the heck out of them.
I have no experience with the Stevens, but, most pumps work most reliably if you work them like you mean it - being too gentle working the pump can make a lot of shotguns bobble.
 
1 - 10 of 10 Posts
Top